In a effort to get my brain thinking about things it should be thinking about I am going to post a short summary of what I intend to cover at my talk.

First, what is the purpose of marriage? According to Catholic teaching, its primary purpose is having and raising children. -- These days, for some reason, this is a very controversial assertion -- The secondary purposes are the mutual growth (help) of the spouses and the "morally regulated satisfaction of the sex urge" (concupiscence).

Second, what is the clear natural order of marriage and sex in terms of the assertion above. What constitutes offenses to that natural order? -- Discuss in terms of the creation narratives. The original intent, as opposed to the allowances in the law. (i.e. the OT part)

Third, why does the Church consider it a Sacrament? (i.e. the NT part) ... I find that this is one of the most critical defenses for Catholics and its not a Bible zinger easy defense. Very important to explain the Ephesians 5 narrative regarding Christ and the Church. Relate even further to imaging the Trinity.

Thats it ... that is what I plan to cover and I expect it to take 90 minutes to 2 hours.